I remember this idea as a big deal in psychology quite a few years back. Two doctors in the 1950’s — Meyer Friedman and Ray Rosenman — said there were psychological and personality traits that doubled the risk of heart attacks in what they termed Type A personalities as opposed to Type B. This Wikipedia article summarizes the theory as I remember it:
The theory A individual as ambitious, rigidly organized, highly status-conscious, sensitive, impatient, take on more than they can handle, want other people to get to the point, anxious, proactive, and concerned with time management. People with Type A personalities are often high-achieving “workaholics” who multi-task, push themselves with deadlines, and hate both delays and ambivalence.
In his 1996 book, Type A Behavior: Its Diagnosis and Treatment, Friedman suggests that Type A behavior is expressed in three major symptoms: free-floating hostility, which can be triggered by even minor incidents; time urgency and impatience, which causes irritation and exasperation usually described as being “short-fused”; and a competitivedrive, which causes stress and an achievement-driven mentality. The first of these symptoms is believed to be covert and therefore less observable, while the other two are more overt.
The theory describes “Type B” individuals as a contrast to those with Type A personalities. People with Type B personality by definition generally live at a lower stress level and typically work steadily, enjoying achievement but not becoming stressed when they do not achieve. When faced with competition, they do not lose their minds and either enjoy the game or back down. They may be creative and enjoy exploring ideas and concepts. They are often reflective, thinking about the outer and inner worlds.”
Critics of the research, according to Wikipedia, said that it was flawed because of the characteristics of the sample and sources of funding came primarily from companies with a vested interest in the results (tobacco companies.) Indeed, the medical consensus now is that the cause of heart attacks is coronary artery disease with lifestyle (smoking), medical, nutritional, and genetic causes rather than personality.
But, Type A and Type B psychological profiling lives on in the culture. I suspect most of us are a combination of A and B. But here are two dogs, what else, that illustrate each type. First, Type A, Jesse, a workaholic Jack Russell Terrier:
Next: Type B, Sprocket, a laid back English Bull Terrier who has … well…a personality all his own. (You might have to turn the volume up a bit for this one.)
Next: J and the Shape($) command (verb.)